JERUSALEM -- Pro-Palestinian activists sent another boat to challenge Israel's blockade of the Gaza Strip on Tuesday and Egypt declared it was temporarily opening a crossing into the Palestinian territory after a botched raid on an aid flotilla that ended with Israeli soldiers killing nine activists.

The raid provoked ferocious international condemnation of Israel, raised questions at home, and appeared likely to increase pressure to end the blockade that has deepened the poverty of the 1.5 million Palestinians living in the strip. Turkey, which unofficially supported the flotilla, has led the criticism, calling the Israeli raid a "bloody massacre."

The pro-Palestinian flotilla had been headed to Gaza with tens of thousands of tons of aid that Israel bans from Gaza. After days of warnings, Israel intercepted the flotilla under the cover of darkness early Monday, setting off a violent melee that left nine activists dead and dozens of people, including seven soldiers, wounded. Most of the dead were believed to be Turks.

Israel said 679 people were arrested, and about 50 of those had left the country voluntarily. Hundreds who refused to cooperate remained jailed and subject to deportation.

Israel says the Gaza blockade is needed to prevent the Iranian-backed Hamas, which has fired thousands of rockets into the Jewish state, from building up its arsenal. It also wants to pressure Hamas to free an Israeli soldier it has held for four years.

Critics say the blockade has failed to weaken Hamas but further strapped an already impoverished economy. It also has prevented Gaza from rebuilding after a devastating Israeli military offensive early last year.

Egypt, which has enforced the blockade with Israel since Hamas militants seized control of Gaza three years ago, said it was opening the border for several days to allow aid into the area.

The governor of Egyptian's northern Sinai district, Murad Muwafi, said it was a humanitarian gesture meant to "alleviate the suffering of our Palestinian brothers after the Israeli attack."

Hundreds of Gaza residents quickly gathered at the border. A steady stream of cars with suitcases on roof racks headed toward the border. Some families carrying packed luggage headed to the border by foot. Hamas police with assault rifles patrolled nearby to maintain order.

"We are working to help residents take advantage of this opportunity," said Hamas Interior Ministry spokesman Ihab Ghussein. "We hope it will be open all the time, not just as a response to yesterday's events."

Greta Berlin said the Free Gaza Movement, which organized the flotilla, would not be deterred and that another cargo boat was off the coast of Italy en route to Gaza. A second boat carrying about three dozen passengers is expected to join it, Berlin said. She said the two boats would arrive in the region late this week or early next week.

"This initiative is not going to stop," she said from the group's base in Cyprus. "We think eventually Israel will get some kind of common sense. They're going to have to stop the blockade of Gaza, and one of the ways to do this is for us to continue to send the boats."